Have a rant, sideline, or tangent that you'd like to go off on - but don't want to include it in the main body of your content?

Unobtrusive Sidenotes to the rescue. This is a "a simple mix of Javascript and CSS that makes it ridiculously easy to incorporate sidenotes into your web pages or blogs." The site includes detailed instructions on how to make this all work, and even includes examples (it looks pretty dang good). — Wendy Boswell